Shadows stir in the north, and an ancient darkness awakens. Far away in Ponyville, what starts as a simple, childish act of spite, puts the entire world in danger. On Hearth's Warming Eve Luna and Celestia discover a disturbing turn of events. The darkness is coming, and the only thing that can stop it is the crystal box. Twilight has left it with Rarity however, and unfortunately for everyone, Sweetie Belle has sold it. Now Rarity must race to find the box and the princesses must race to save the world, while Sweetie Belle simply prays she isn't grounded for life.